Previous studies have shown that the types of treatment received by psychiatric patients are related to patient social class and that psychiatrists demonstrate clusters of attitudes associated with hypothesized therapeutic orientations. A mailed questionnaire survey of psychiatrists practicing in Maryland was conducted to elucidate the impact of extra-patient variables and contextual variables on the delivery of psychiatric services. Completed questionnaires were received from 482 (80.5%) of 599 possible respondents. Comparisons between respondents and non-respondents and between the study sample and a national sample of psychiatrists indicate that findings in the study population have general applicability to the United States. The magnitude of the relationships between attributes of the psychiatrists themselves, the settings and conditions of their work, and their use of particular treatments will be explored through multiple regression analyses of the relative use of each of 8 types of treatment on other variables. Additional analyses will compare high and low users of five particular classes of treatment: (1) electroshock therapy, (2) pharmacotherapy, (3) social treatments, (4) psychoanalysis, and (5) behavior therapy. This dissertation project uses the methods of epidemiology and the sociology of medicine to study the delivery of psychiatric services. The long-term objective of the project is to quantify the effects of extra-patient variables on service delivery in order to: (1) increase our understanding of physicians' treatment behavior, (2) improve the accuracy of predictions of manpower and health resources needs, and (3) aid in assessing the differences between services provided in the public sector and services provided in the private sector.